/* Blob.js
 * A Blob implementation.
 * 2014-07-24
 *
 * By Eli Grey, http://eligrey.com
 * By Devin Samarin, https://github.com/dsamarin
 * License: MIT
 *   See https://github.com/eligrey/Blob.js/blob/master/LICENSE.md
 */

/*global self, unescape */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
 plusplus: true */

/*! @source http://purl.eligrey.com/github/Blob.js/blob/master/Blob.js */

(function (view) {
	"use strict";

	view.URL = view.URL || view.webkitURL;

	if (view.Blob && view.URL) {
		try {
			new Blob;
			return;
		} catch (e) {}
	}

	// Internally we use a BlobBuilder implementation to base Blob off of
	// in order to support older browsers that only have BlobBuilder
	var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || (function(view) {
			var
				get_class = function(object) {
					return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
				}
				, FakeBlobBuilder = function BlobBuilder() {
					this.data = [];
				}
				, FakeBlob = function Blob(data, type, encoding) {
					this.data = data;
					this.size = data.length;
					this.type = type;
					this.encoding = encoding;
				}
				, FBB_proto = FakeBlobBuilder.prototype
				, FB_proto = FakeBlob.prototype
				, FileReaderSync = view.FileReaderSync
				, FileException = function(type) {
					this.code = this[this.name = type];
				}
				, file_ex_codes = (
					"NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR "
					+ "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
				).split(" ")
				, file_ex_code = file_ex_codes.length
				, real_URL = view.URL || view.webkitURL || view
				, real_create_object_URL = real_URL.createObjectURL
				, real_revoke_object_URL = real_URL.revokeObjectURL
				, URL = real_URL
				, btoa = view.btoa
				, atob = view.atob

				, ArrayBuffer = view.ArrayBuffer
				, Uint8Array = view.Uint8Array

				, origin = /^[\w-]+:\/*\[?[\w\.:-]+\]?(?::[0-9]+)?/
				;
			FakeBlob.fake = FB_proto.fake = true;
			while (file_ex_code--) {
				FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
			}
			// Polyfill URL
			if (!real_URL.createObjectURL) {
				URL = view.URL = function(uri) {
					var
						uri_info = document.createElementNS("http://www.w3.org/1999/xhtml", "a")
						, uri_origin
						;
					uri_info.href = uri;
					if (!("origin" in uri_info)) {
						if (uri_info.protocol.toLowerCase() === "data:") {
							uri_info.origin = null;
						} else {
							uri_origin = uri.match(origin);
							uri_info.origin = uri_origin && uri_origin[1];
						}
					}
					return uri_info;
				};
			}
			URL.createObjectURL = function(blob) {
				var
					type = blob.type
					, data_URI_header
					;
				if (type === null) {
					type = "application/octet-stream";
				}
				if (blob instanceof FakeBlob) {
					data_URI_header = "data:" + type;
					if (blob.encoding === "base64") {
						return data_URI_header + ";base64," + blob.data;
					} else if (blob.encoding === "URI") {
						return data_URI_header + "," + decodeURIComponent(blob.data);
					} if (btoa) {
						return data_URI_header + ";base64," + btoa(blob.data);
					} else {
						return data_URI_header + "," + encodeURIComponent(blob.data);
					}
				} else if (real_create_object_URL) {
					return real_create_object_URL.call(real_URL, blob);
				}
			};
			URL.revokeObjectURL = function(object_URL) {
				if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) {
					real_revoke_object_URL.call(real_URL, object_URL);
				}
			};
			FBB_proto.append = function(data/*, endings*/) {
				var bb = this.data;
				// decode data to a binary string
				if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
					var
						str = ""
						, buf = new Uint8Array(data)
						, i = 0
						, buf_len = buf.length
						;
					for (; i < buf_len; i++) {
						str += String.fromCharCode(buf[i]);
					}
					bb.push(str);
				} else if (get_class(data) === "Blob" || get_class(data) === "File") {
					if (FileReaderSync) {
						var fr = new FileReaderSync;
						bb.push(fr.readAsBinaryString(data));
					} else {
						// async FileReader won't work as BlobBuilder is sync
						throw new FileException("NOT_READABLE_ERR");
					}
				} else if (data instanceof FakeBlob) {
					if (data.encoding === "base64" && atob) {
						bb.push(atob(data.data));
					} else if (data.encoding === "URI") {
						bb.push(decodeURIComponent(data.data));
					} else if (data.encoding === "raw") {
						bb.push(data.data);
					}
				} else {
					if (typeof data !== "string") {
						data += ""; // convert unsupported types to strings
					}
					// decode UTF-16 to binary string
					bb.push(unescape(encodeURIComponent(data)));
				}
			};
			FBB_proto.getBlob = function(type) {
				if (!arguments.length) {
					type = null;
				}
				return new FakeBlob(this.data.join(""), type, "raw");
			};
			FBB_proto.toString = function() {
				return "[object BlobBuilder]";
			};
			FB_proto.slice = function(start, end, type) {
				var args = arguments.length;
				if (args < 3) {
					type = null;
				}
				return new FakeBlob(
					this.data.slice(start, args > 1 ? end : this.data.length)
					, type
					, this.encoding
				);
			};
			FB_proto.toString = function() {
				return "[object Blob]";
			};
			FB_proto.close = function() {
				this.size = 0;
				delete this.data;
			};
			return FakeBlobBuilder;
		}(view));

	view.Blob = function(blobParts, options) {
		var type = options ? (options.type || "") : "";
		var builder = new BlobBuilder();
		if (blobParts) {
			for (var i = 0, len = blobParts.length; i < len; i++) {
				if (Uint8Array && blobParts[i] instanceof Uint8Array) {
					builder.append(blobParts[i].buffer);
				}
				else {
					builder.append(blobParts[i]);
				}
			}
		}
		var blob = builder.getBlob(type);
		if (!blob.slice && blob.webkitSlice) {
			blob.slice = blob.webkitSlice;
		}
		return blob;
	};

	var getPrototypeOf = Object.getPrototypeOf || function(object) {
			return object.__proto__;
		};
	view.Blob.prototype = getPrototypeOf(new view.Blob());
}(typeof self !== "undefined" && self || typeof window !== "undefined" && window || this.content || this));